Health Alert: Warrants immediate action or attention. Health Advisory: Provides information for a specific incident or situation; may not require fimmediate action. Health Update: Provides updated information regarding an incident or situation; unlikely to require immediate action

Health Alert

Date: April 3, 2008

From: Hugh F. Stallworth, MD, MPH, Health Officer 755-8942 Lisa B. Hernandez, MD, MPH, Deputy Health Officer 755-4585

Measles outbreaks: Control and response in healthcare settings

These cases serve as a reminder to healthcare providers of the ongoing risk of measles importations, the importanance of vaccinations and prompt response.No cases of measles have been reported in Monterey County

Current Outbreak

A measles outbreak linked to an importation from Switzerland currently is ongoing in Arizona. The first case, with rash onset on February 12, 2008, occurred in an adult visitor from Switzerland who was hospitalized with measles and pneumonia. This hospital admission prompted verification of the measles immune status of approximately 1800 healthcare personnel and vaccination of those without evidence of immunity. Through March 31, 2008, nine confirmed cases have been reported to the Arizona Department of Health Services, and there are two suspected cases (one in a Colorado resident) and hundreds of contacts under investigation. The nine case-patients range in age from 10 months to 50 years. All but one were infected in healthcare settings, one of the five adult case-patients is a healthcare worker, and all cases were unvaccinated at the time of exposure.

 

Recent Outbreaks

In January and February 2008, San Diego experienced an outbreak of 11 measles cases, with an additional case-patient who was exposed in San Diego but became ill in Hawaii. The index case was an unvaccinated child who had recently traveled to Switzerland, where a measles outbreak is ongoing.

Transmission in this outbreak occurred in a doctor's office as well as in community settings. The same genotype was identified from more than one case in the San Diego and Arizona outbreaks; this genotype is currently circulating in Switzerland. Confirmed measles cases also have been reported from New York City (importation from Isreal) and from Virginia (importation from India). In addition, two measles cases recently confirmed in unvaccinated siblings from Michigan may have resulted from exposure during a long stop-over in the Atlanta airport.

Risk to Healthcare Providers

Although measles is no longer an endemic disease in the United States, it remains endemic in most countries of the world, including some countries in Europe. Large outbreaks currently are occurring in Switzerland and Israel. In the United States this year there have been 24 confirmed cases of measles

Health Alert: Warrants immediate action or attention. Health Advisory: Provides information for a specific incident or situation; may not require immediate action. Health Update: Provides updated information regarding an incident or situation; unlikely to require immediate action resulting from importations from endemic countries that have been reported to the Centers for Disease Control and Prevention (CDC). These cases highlight the ongoing risk of measles importations, the risk of spread in susceptible populations, and the need for a prompt and appropriate public health response to measles cases. Because of the severity of the disease, people with measles commonly present in physician's offices or emergency rooms and pose a risk of transmission to other patients and healthcare personnel in these and in inpatient hospital settings. Healthcare providers should remain aware that measles cases may occur in their facility and that transmission risks can be minimized by ensuring that all healthcare personnel have evidence of measles immunity and that appropriate infection control practices are followed.

Transmission and case definition

Measles is a highly contagious disease that is transmitted by respiratory droplets and airborne spread. The disease can result in severe complications, including pneumonia and encephalitis. The incubation period for measles ranges from 7 to 18 days. The diagnosis of measles should be considered in any person with a generalized maculopapular rash lasting ≥ 3 days, a temperature ≥ 101ºF (38.3ºC), and cough, coryza, or conjunctivitis. Immunocompromised patients may not exhibit rash or may exhibit an atypical rash.

Response

Rapid and aggressive public health action is needed to respond to measles cases so it is critical that providers report suspect measles cases to the Monterey County Health Department's Communicable Disease Unit (831-755-4521).

Investigation and Treatment of Contacts

Case investigation and vaccination of household or other close contacts without evidence of immunity should not be delayed pending the return of laboratory results. Preparation for other control activities may need to be initiated before laboratory results are known. Control activities include isolation of known and suspected case-patients and administration of vaccine (at any interval following exposure) or immune globulin (within 6 days of exposure, particularly contacts ≤ 6 months of age, pregnant women, and immunocompromised people, for whom the risk of complications is highest) to susceptible contacts. For contacts who remain unvaccinated, control activities include exclusion from day care, school, or work and voluntary home quarantine from 7 to 21 days following exposure. Persons who are known contacts of measles patients and who develop fever and/or rash should be considered suspected measles case-patients and be appropriately evaluated by a healthcare provider.

Assesment of Suspect Cases

If healthcare providers are aware of the need to assess a suspected measles case, they should schedule the patient at the end of the day after other patients have left the office and inform clinics or emergency rooms if they are referring a suspected measles patient for evaluation so that airborne infection control precautions can be implemented prior to their arrival.

Travel Assesment

Healthcare providers should maintain vigilance for measles importations and have a high index of suspicion for measles in persons with a clinically compatible illness who have traveled abroad or who have been in contact with travelers. They should assess measles immunity in U.S. residents who travel abroad and vaccinate if necessary. Measles outbreaks are ongoing in Switzerland and Israel, and measles outbreaks are common throughout Europe. Measles is endemic in many countries, including popular travel destinations, such as Japan and India. Suspected measles cases should be reported immediately to Health Alert: Warrants immediate action or attention. Health Advisory: Provides information for a specific incident or situation; may not require immediate action. Health Update: Provides updated information regarding an incident or situation; unlikely to require immediate action the Monterey County Communicable Disease Unit and serologic and virologic specimens (serum and throat or nasopharyngeal swabs) should be obtained for measles virus detection and genotyping.

Preventing transmission in healthcare settings

To prevent transmission of measles in healthcare settings, airborne infection control precautions should be followed stringently. Suspected measles patients (i.e., persons with febrile rash illness) should be removed from emergency department and clinic waiting areas as soon as they are identified, placed in a private room with the door closed, and asked to wear a surgical mask, if tolerated. In hospital settings, patients with suspected measles should be placed immediately in an airborne infection (negative-pressure) isolation room if one is available and, if possible, should not be sent to other parts of the hospital for examination or testing purposes.

All healthcare personnel should have documented evidence of measles immunity on file at their work location. Having high levels of measles immunity among healthcare personnel and such documentation on file minimizes the work needed in response to measles exposures, which cannot be anticipated. Recent measles exposures in hospital settings in three states necessitated verifying records of measles immunity for hundreds or thousands of hospital staff, drawing blood samples for serologic evidence of immunity when documentation was not on file at the work site, and vaccinating personnel without evidence of immunity.

Recommendations for vaccination

Measles is preventable by vaccination. MMR vaccine is routinely recommended for all children at 12–15 months of age, with a second dose recommended at age 4–6 years. Two doses of MMR vaccine are recommended for all school students and for the following groups of persons without evidence of measles immunity: students in post–high school educational facilities, healthcare personnel, and international travelers who are ≥ 12 months of age. Other adults without evidence of measles immunity should routinely receive one dose of MMR vaccine. To prevent acquiring measles during travel, U.S. residents

aged ≥ 6 months traveling abroad should be vaccinated or have documentation of measles immunity before travel. Infants 6–11 months of age should receive one dose of monovalent measles vaccine (or MMR vaccine if monovalent vaccine is not available) prior to travel. During a measles outbreak, additional vaccine recommendations should be considered: 1) children ≥ 12 months of age should receive their first dose of MMR vaccine as soon after their first birthday as possible and their second dose 4 weeks later, 2) healthcare facilities should strongly consider recommending one dose of MMR vaccine to unvaccinated healthcare personnel born before 1957 who do not have serologic evidence of immunity or physician documentation of measles disease, and 3) one dose of measles or MMR vaccine should be considered for infants ≥ 6 months of age.

Additional Sources of Information

Centers for Disease Control

Measels Vaccination - http://www.cdc.gov/vaccines/vpd-vac/measles

Travelers Health - http://wwwn.cdc.gov/travel

Infection Control in Healthcare Settings - http://www.cdc.gov/ncidod/dhqp